The purpose of this study was to investigate eighth grade students' skills in different problem-posing situations. Problem-posing situations include free, semi-structured and structured problem-posing situations. The study was conducted using case study methodology, which is within the scope of descriptive research. The study was conducted with 166 eighth grade students (ages 13-15). The Problem-Posing Test was used as a data collection tool. In the analysis of the data, an analytical rubric developed by the researchers was used. The problem-posing assessment criteria were mathematical expression, language, suitability for acquisitions, quantity and quality of data, solvability, originality and presence of the solution. The data were analysed descriptively with a qualitative approach. It was observed that the students had generally low success in different problem-posing activities. In this research, the students were found to be more successful in semi-structured problem-posing situation than free and structured problem-posing situations when each problem-posing situation was examined separately. It was found that the majority of the problems the students posed were routine problems. It was determined that the students mostly used "writing an equation" and "drawing a shape" strategies for the solutions of the problems they posed in different problem-posing situations.